The Omnivore's Dilemma - Michael Pollan [85]
That conventional supply chain begins with the clever machine Earthbound developed to harvest baby greens: a car-size lettuce-shaving machine that moves down the rows, cutting the baby greens at a precise point just above the crown. Spidery arms extended in front of the machine gently rake through the bed in advance of the blade, scaring off any mice that might find their way into the salad. A fan blows the cut leaves over a screen to shake out any pebbles or soil, after which a belt conveys the greens into white plastic totes that workers stack on pallets on a wagon trailing alongside. At the end of each row the pallets are loaded onto a refrigerated tractor trailer, entering a “cold chain” that will continue unbroken all the way to the produce section at your supermarket.
Earthbound’s own employees (who receive generous benefits by Valley standards, including health insurance and retirement) operate the baby greens harvester, but on the far side of the field I saw a contract crew of Mexicans, mostly women, slowly moving through the rows pulling weeds. I noticed that some of the workers had blue Band-Aids on their fingers. The Band-Aids are colored so inspectors at the plant can easily pick them out of the greens; each Band-Aid also contains a metal filament so that the metal detector through which every Earthbound leaf passes will pick it up before it winds up in a customer’s salad.
Once filled, the trucks deliver their cargo of leaves to the loading dock at the processing plant in San Juan Bautista, essentially a 200,000-square-foot refrigerator designed to maintain the lettuce at exactly thirty-six degrees through the entire process of sorting, mixing, washing, drying, and packaging. These employees, most of them Mexicans, are dressed in full-length down coats; they empty totes of arugula, radicchio, and frisée into stainless steel rivers of lightly chlorinated water, the first of three washes each leaf will undergo. Viewed from overhead, the lettuce-packing operation looks like a hugely intricate Rube Goldberg contraption, a tangle of curving silver watercourses, shaking trays, and centrifuges, blue Band-Aid detectors, scales, and bagging stations that in about a half hour propels a freshly harvested leaf of baby lettuce into a polyethylene bag or box of ready-to-dress spring mix. The plant washes and packs 2.5 million pounds of lettuce a week; when you think just how many baby leaves it takes to make a pound, that represents a truly stupendous amount of lettuce. It also represents a truly stupendous amount of energy: to run the machines and chill the building, not to mention to transport all that salad to supermarkets across the country in refrigerated trucks and to manufacture the plastic containers it’s packed in. A one-pound box of prewashed lettuce contains 80 calories of food energy. According to Cornell ecologist David Pimentel, growing, chilling, washing, packaging, and transporting that box of organic salad to a plate on the East Coast takes more than 4,600 calories of fossil fuel energy, or 57 calories of fossil fuel energy for every calorie of food. (These figures would be about 4 percent higher if the salad were grown conventionally.)
I had never before spent quite so much time looking at and thinking about lettuce, which when you do think about it—at least in the confines of the world’s biggest refrigerator packed to the rafters with the stuff—is truly peculiar stuff. There are few things humans eat that are quite so elemental—a